Devices and methods for controlling headspace humidity and oxygen levels

ABSTRACT

A humidity control device for use in maintaining the desired humidity of a closed environment, e.g., a container, while also decreasing headspace oxygen, the device including a water vapor and oxygen permeable pouch, an aqueous salt solution containing humidity controlling salts in combination with salts of ascorbic acid or isomers thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

None

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

Field of the Invention

The disclosure relates to generally to devices and methods for thepreservation of substances and object that are sensitive to oxygen andhumidity. More specifically, certain foods, pharmaceuticals, botanicalsand herbs may benefit.

Description of the Related Art

Many foods and botanicals or herbs, such as cannabis, are most stableand best consumed at a certain water activity. These substances are alsosubject to degradation due to the chemical reaction of certaincomponents with oxygen found in the surrounding atmosphere frequentlycalled headspace. For example, the unsaturated lipids in food productsand the terpenes in cannabis readily react with molecular oxygen to formundesirable oxidation products, thus degrading the quality and even theefficacy of the food or botanical.

As disclosed in U.S. Pat. No. 5,936,178, the relative humidity of closedenvironments can be stabilized by the use of humidity control systemscomprised of moisture permeable pouches containing specific saltsolutions. Also, certain non-ionic solutions containing low molecularweight molecules such as ethylene glycol, propylene glycol, glycerin,urea, guanidine, ethanol amine, simple sugars, or sugar alcohols may beemployed. The choice of the solute and the solute concentration in anaqueous solution determines the solution water activity (aw). A solutionof a certain water activity will equilibrate with the surroundingatmosphere until the relative humidity (RH) is equivalent to the wateractivity multiplied by 100. That is, the RH percentage will equal thewater activity ×100. For example, an aqueous solution of saturatedsodium chloride with excess crystals, aw 0.75 will equilibrate with themoist air or dry air in a closed system until a relative humidity of 75percent is achieved.

The moisture transfer capacity (MTC) is defined as the amount ofmoisture transferred, into or out of, a given control system, i.e.device, pouch, etc., over a defined relative humidity range. Forexample, a saturated solution of sodium chloride can transfer about 65%moisture, maintaining a water activity of 0.75. Clearly an aqueoussystem would be required to have sufficient MTC to maintain the RH ofcertain products.

The choice of salt solution is not only important because of its abilityto define the relative humidity, the salt must not chemically degradethe pouch film construction or emit, outgas, corrosive or obnoxioussubstances.

A number of dry oxygen absorbing packets are currently marketed. Theseinclude brand names like AGELESS®, StayFresh® and FreshPax®. Thetechnology is based on the chemical reaction of oxygen with a metal,typically iron. U.S. Pat. No. 4,127,503 describes this technology and isincorporated herein in its entirety by reference. More recently, U.S.Pat. No. 8,048,201, also incorporated herein in its entirety byreference, discloses a system comprised of a wicking agent, malic acidand iron at pH 2 to 3. The wicking agent absorbs atmospheric water andactivates the acid which reacts with iron to consume oxygen. Thesesystems are very efficient and are commonly employed to decreaseheadspace oxygen in a variety of applications. These systems, however,are not dual action humidity and oxygen control. These oxygen scavengersystems are packaged in films that are readily permeable to oxygen, butnot necessarily suitable to fulfill the dual function of humiditycontrol and oxygen elimination disclosed in this patent.

Further, in U.S. Pat. No. 6,921,026, commonly owned by the currentassignee Boveda, Inc., Saari discloses a method for the dual control ofheadspace humidity and oxygen comprised of an aqueous salt solution andelemental iron. U.S. Pat. No. 6,921,026 is incorporated by referenceherein in its entirety. While this method controls humidity, the rate ofoxygen reaction with the metal is too slow to be of commercial valueand, therefore, is susceptible to improvement. Ascorbic acid saltschemically react with molecular oxygen to form hydrogen peroxide anddehydroascorbic acid salts. The hydrogen peroxide is consumed by furtherreacting with ascorbic acid, dehydroascorbic acid salts to formtetahydroxydiketohexanoic acid salts. See Deutsch, J C, Anal. Biochem,1998, Jan. 1; 255(1):1-7, also incorporated herein in its entirety byreference. Clearly isomers of ascorbic acid such as erythorbic acidsalts will behave in a similar fashion.

While this ascorbate oxidation reaction has been employed to removedissolved oxygen from boiler water as taught by U.S. Pat. No. 4,891,141,incorporated herein in its entirety by reference, the use of thisreaction mixed with inorganic salts to decrease headspace oxygen has notbeen reported. Furthermore, it was discovered that metallic iron inconjunction with the ascorbate salt increased the rate of oxygenheadspace removal.

Accordingly, there exists a need for an improved method to controlheadspace humidity and oxygen by combining certain salt solutions withascorbic acid salts or isomers thereof alone or in combination with ironbetween pH 6 and 10.

BRIEF SUMMARY OF THE INVENTION

The present invention provides devices in the form of packets or pouchescontaining liquid systems in the form of humidity and oxygen controlsolutions for controlling the relative humidity and oxygen in agenerally closed environment, e.g., an enclosure comprising a closuremechanism such as a lidded container. This invention discloses preferredsystems providing superior moisture transfer capacity for stabilizingthe relative humidity and oxygen. The disclosed formulas providesuperior moisture transfer capacity without undo outgas, or packagedegradation. In a preferred form, the present invention employs asaturated aqueous solution in combination with ascorbate salts orisomers such as erythorbate. These solutions may be contained in certainpolymeric films that will allow the transfer of moisture vapor andoxygen without transfer of the liquid solution.

Certain thickening agents may be added to these solutions in order toincrease the viscosity. A high viscosity product will minimizeundesirable solution leakage in the event of a package defect as well asaffect the nature of crystal formation. Many potential thickening agentswere disclosed in U.S. Pat. No. 5,936,178 discussed supra. In thepresent invention, the preferred thickening agents includehydroxyethylcellulose (Natrosol®) and xanthan gum.

The various embodiments of the humidity and oxygen control solutiondisclosed herein in accordance with this invention are introduced intopouches formed at least partly from polymeric films that breathe in amanner such that they will transport moisture vapor and oxygen but willcontain the solution without leaking liquid. The water vapor transport,known as water vapor transmission rate (WVTR) is measured in terms ofgrams of water passed per 100 square inches of material per 24 hoursunder standard test conditions. It is a function of the type of filmused and the thickness of the film. The total moisture transferred, ofcourse, is also determined by the area of film exposed to a humiditycontrol solution in a given application. It has been shown that a WVTRof about 60 grams water per 100 square inches over 24 hours providesgood results for a device in accordance with the invention. Packagingfilm materials that may be employed include fibrous polyethylene(TYVEK®), polyesters such as the elastomer Hytrel®, or polyamide Pebaxlaminated onto a suitable substrate such as paper.

However, the relative humidity control device is not limited to apolymeric film pouch. Any container or material that will transportwater vapor while retaining the liquid can provide a suitable containerfor the humidity control solutions of the invention. The thermal formedbottle lid shown in FIG. 1 is an example of a container which, whenformed from Hytrel or suitable alternative, will control the oxygen andhumidity in an essentially closed container.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates a perspective view of one embodiment of the presentinvention;

FIG. 2 illustrates a perspective view of one embodiment of the presentinvention; and

FIG. 3 illustrates a side cutaway view of one embodiment of the preventinvention.

DETAILED DESCRIPTION OF THE INVENTION

The following describes one or more embodiments of the present inventionin detail offered by way of example and is not meant to limit the scopeof the invention as other combinations and variations may occur to thoseskilled in the art that are well within the scope of the inventiveconcept.

The present invention comprises a liquid humidity and oxygen controldevice comprising a polymeric film pouch having at least some wallssufficiently permeable to permit migration of water vapor and oxygenthrough the film and yet thick and impervious enough to prevent theescape of liquids. The control device may be used to control humidityand oxygen within a generally closed environment including but notlimited to, an enclosure such as a container with a removable cap suchas a glass jar for protecting the contents stored therein. The controldevice may be incorporated into the removable lid in certain embodimentsor may be provided in addition to the removable lid. Certain embodimentscomprise the control device being sealed against the upper surface of aglass jar by a removable cap. Alternatively, a control pouch comprisingthe aqueous humidity and oxygen control solution may be placed withinthe container.

A headspace may exist within the exemplary container, in addition to thecontents within the container that require humidity and oxygen control.

Certain preferred embodiments may employ an aqueous humidity controlsolution including sodium formate, potassium citrate, potassium chlorideor sodium chloride with or without a thickening agent such as xanthangum.

Chemically reactive ascorbate and erythorbate salts may be included inthe solution to eliminate oxygen which diffuses from the headspace,through the semi-permeable film to the liquid contents.

Very fine particles of iron may be added to the solution to enhance theoxygen reactivity. It was discovered that without the presence of theascorbate isomers, the iron in this liquid oxidizes at a very slow rate.The solutions may contain excess solute to increase the capacity of thedevice to remove water vapor from the surroundings.

The polymeric film pouch may be constructed of any size or shapenecessary to hold the amount of solution necessary to stabilize thehumidity and oxygen of the environment, e.g., a container such as aglass jar with closed lid. For example, a typical device to maintain thehumidity and oxygen level in a pint jar containing 10 grams of cannabismay comprise a pillow-like, water vapor and oxygen-permeable pouchcontaining about 8 grams of control solution.

The pouch of the present invention may be constructed of any polymericmaterial that contains the solution, but has a sufficient water vaportransmission rate and a sufficient oxygen transmission rate. A preferredpackaging material comprises a thermoplastic polyester elastomer soldunder the trademark Hytrel®. The polymeric material of the pouch may beselected from the group consisting of polyesters, polyamides, polylactate, polyolefin, and combinations thereof.

The preferred range of water vapor transmission rate for the pouchmaterial is one that transmits moisture from about 1 percent to about 40percent by weight of the initial total package contents over a 24-hourperiod in an atmosphere of less than 10% relative humidity and whereinthe pouch absorbs moisture from about 1 percent to about 40 percent byweight of total initial package contents over a 24-hour period in anatmosphere greater than 85 percent relative humidity.

The skilled artisan will now readily recognize moisture transmission andabsorption preferred ranges, each of which are based on a referencetemporal value of 24 hours combined with, in the case of transmission,an atmosphere of less than 10% relative humidity and, in the case ofabsorption, an atmosphere greater than 85% relative humidity. Thus, itwill be appreciated that if the temporal value and and/or relativehumidity value are changed from those stated reference values, thetransmission and/or absorption values, respectively, will also changeaccordingly. Each of these transmission and absorption values are withinthe scope of the present invention so long as the preferred transmissionand absorption values, as described above, at the reference temporal andrelative humidity values, is satisfied.

In addition to the moisture transfer capability, the packaging film musttransmit oxygen at a sufficient rate. The preferred range of oxygenpermeability of the pouch material is such that it will transfer ortransmit therethrough a minimum of 0.2 ml of headspace oxygen per squareinch per 24-hour period at 70 degrees F. and atmospheric pressure.

The skilled artisan will now readily recognize that the preferred oxygenpermeability is provided at given reference temperature and atmosphericpressure values and that, if the temperature and and/or atmosphericpressure values are changed from those reference values, the oxygenpermeability will also change accordingly. Each of these oxygenpermeability values are within the scope of the present invention solong as the preferred oxygen permeability, as described above, at thereference temperature and atmospheric pressure values is satisfied.

The preferred water vapor and oxygen permeable pouch materials includepouches comprising polymeric materials such as polyester, Hytrel®, orpolyether block amide Pebax® that transmits water vapor, but not liquidwater. Any material that meets the basic criteria might be used. Anyreceptacle that transmits water vapor and oxygen as desired and providesa barrier to liquids can be used. In addition, the moisture controlsystem, sealed pouch may be contained in a second (outer) water vaporpermeable pouch, bag or other container in order to provide back-upprotection if the primary pouch should leak. Some, or all, of thecontrol device pouch may be comprised of the water vapor and oxygenpermeable materials described herein.

The solutions disclosed in this invention may contain from 15% to 75%water depending on the humidity of the environment to be controlled. Thesodium formate, sodium chloride and potassium citrate are used to obtainthe optimal humidity control, and certain formulations may contain anexcess of these components, generally as crystals. Although thickeningagents are not required or instrumental in controlling humidity, thehumidity control solutions may be thickened to improve processing andminimize potential leaks. Although different thickeners can potentiallybe employed, brine tolerant xanthan gum (Danisco® SM) is preferred. Thexanthan gum may be used at levels ranging from 0.1% to 0.7% to achievethe desired viscosity which is in the range of about 500 to about 7000centipoise. In addition, the pouch device may comprise a vapor-permeableouter pouch for containing said pouch as a further protection againstleaks.

The pH of the solution may be adjusted using common acids or bases suchas, but not limited to, citric acid, lactic acid, formic acid,phosphoric acid, phosphate salts, sodium hydroxide, or potassiumhydroxide. A preferred pH range is from about 6.0 to about 10.0.Ascorbic acid, erythorbic acid and their salts are preferred. Very smallparticles of iron are preferred due to the increased surface area andthus chemical reactivity.

A particular embodiment of the inventive salt solution within theinventive humidity and oxygen permeable pouch may comprise:

a saturated aqueous salt solution,

salts of ascorbate isomers containing an amount of a salt solution fromabout 5% to 70% salt, and ascorbic acid salts, or isomers thereof, from5 to 60%.

In addition, wherein the exemplary salt solution may comprise cationsand anions, wherein the cations are selected from the group consistingof: lithium, sodium, potassium, calcium, and magnesium, and the anionsare selected from the group consisting of: chloride, formate, acetate,phosphate, sulfate, citrate, lactate, malate and tartrate.

The exemplary salt solution may further comprise non-ionic substancesselected from the group consisting of propylene glycol, glycerin, and atleast one simple sugar, wherein the at least one simple sugar isselected from the group consisting of: glucose and fructose and sugaralcohols, and wherein the sugar alcohol is selected from the groupconsisting of: xylitol, sorbitol and mannitol.

The exemplary salt solution may comprise a pH that is between 6.0 and10, wherein the pH of the exemplary salt solution may be adjusted byadding an amount of an acid or base selected from the group consistingof citric acid, lactic acid, formic acid, phosphoric acid, phosphatesalts, sodium hydroxide, and potassium hydroxide.

The exemplary salt solution may contain ascorbate isomer salts and/orerythorbic isomer salts, wherein the ascorbate isomer salts comprisesodium salts of ascorbic acid and/or potassium salts of ascorbic acid,and wherein the erythorbic isomer salts comprise sodium salts oferythorbic acid and/or potassium salts of erythorbic acid and, in someembodiments, at least one metal. In some embodiments, the at least onemetal comprises iron including elemental iron.

The exemplary salt solution may contain a ferrous salt, e.g., ferroussulfate.

The exemplary salt solution may be thickened by an amount of one or morecompatible viscosity control agents selected from the group consistingof chemically modified cellulose and xanthan gum.

Operation

In use, the humidity and oxygen control devices of the present inventionare placed in a sealed enclosure containing the material to be protectedby oxygen elimination and controlled humidity. For example, one or morepouches may be placed in a jar or plastic container enclosure withcannabis. Theoretically, if the pouch is sized correctly and the productcontainer enclosure has a perfect seal, oxygen would be eliminated andthe controlled humidity would be maintained indefinitely. However,actual environments are less than ideal and containers tend to leak andmay be opened and closed from time to time. Accordingly, a given pouchof the present invention will gain water or lose water in such a fashionas to protect the contents until the pouch has gained or lost waterexceeding its moisture transfer capacity. Headspace oxygen will diffuseinto the pouch and be consumed by the ascorbate or erythorbate saltsuntil they are totally oxidized or all of the headspace oxygen isconsumed.

FIGS. 1 and 2 illustrate one example of the present invention. FIG. 1illustrates one embodiment of a control pouch 10 comprising a generallycircular backing 12 that is neither water nor oxygen permeable and witha water and oxygen permeable pouch 14 attached thereto. The inventiveaqueous solution as described herein is provided within permeable pouch14. A circular portion 16 of the circular backing 12 is left uncovered.The circular portion 16 is sized to engage a top surface 18 of theexemplary glass jar container 20. Glass jar 20 further comprises threads22 and an interior volume 24. A threaded lid 26 is also provided to sealthe control pouch 10 such that the circular portion 16 of the circularbacking is engaging the top surface 18 of glass jar container 20 andwherein the exemplary pouch 14 is disposed within the interior volume 24of the glass jar container 20. The contents to be protected (not shown)are placed within the interior volume 24 prior to sealing the container.The portion of the interior volume 24 that is not occupied by thecontents to be protected therein comprises the headspace as is wellknown to the skilled artisan. The impermeable circular backing material12 prevents water vapor or oxygen from entering or exiting the interiorvolume 24 once the container is sealed.

Circular portion 16 may, in certain embodiments, comprise an adhesivematerial to assist in securing the control pouch 10 to the top surface18 of glass jar container 20. As will be appreciated, the circularbacking 12 may be sized to accommodate various sizes of glass jarcontainers, specifically circular backing 12 may comprise a diameterthat matches the diameter of the top surface 18 of glass jar container20.

In other embodiments, control pouch 10 may be simply placed within acontainer. Some of these embodiments need not necessarily comprisecircular backing 12.

WORKING EXAMPLES Example 1A

In one embodiment of the present invention, an aqueous solution ofpotassium chloride and sodium erythrobate is prepared by adding 20.9grams of potassium chloride, 16.7 grams of erythorbic acid, and 0.2grams of potassium sorbate to 55 grams of water. Potassium hydroxide(7.2 grams) is carefully added to this mixture. The pH of this solutionis 8.0 and the relative humidity 82% (water activity 0.82). Eight gramsof this solution was filled into a pouch comprised of Hytrel® film(DuPont) (1.5×10−3 inches thick) on a paper substrate. The pouchmeasures 2.5 inches by 2.75 inches with a 5 mm heat seal on three sides.When placed in a dry atmosphere (10% RH), this device emitted 40% of thesolution weight as moisture before it reached 80% RH (aw 0.80).

When this device was placed in a 240 ml metalized package at 70 degreesF. with air headspace, a pouch containing 8.0 grams of the abovesolution consumed 38 ml of oxygen in 19 days.

Example 1B

Example 1 was repeated with the addition of 0.8 grams of 500 mesh ironadded to the 8.0 gram Hytrel® pouch. When placed in a 240 ml metalizedpackage at 70 degrees F. with air headspace, this pouch consumed 50 mlof oxygen in 19 days.

Example 2A

In another embodiment of the present invention, an aqueous solution ofpotassium citrate and potassium erythorbate was prepared by adding 58.0grams of potassium citrate monohydrate, 10.0 grams of erythorbic acid,3.3 grams of potassium hydroxide and 0.2 grams of xanthan gum to 28.5grams of water. The pH of the solution was 7.6 and the water activity0.60 (RH 60%). Eight grams of this solution was filled into a Hytrel®pouch as described in Example 1A. When placed in a dry atmosphere, thisdevice emitted 20% moisture to a water activity of 0.55 (55% RH). In ahigh humidity environment (85% RH), this device gained 10% moisturebefore reaching 69% RH (aw 0.69).

When this device was placed in a 240 ml metalized package at 70 degreesF. with air headspace, a pouch containing 8.0 grams of this solutionconsumed 26 ml of oxygen in 7 weeks.

Example 2B

Example 2 was repeated with the addition of 0.4 grams of 500 mesh ironadded to the 8.0 gram Hytrel® pouch. When placed in a 240 ml metalizedpackage at 70 degrees F. with air headspace, this pouch consumed 32 mlof oxygen in 7 weeks.

Example 3A

In another embodiment of the present invention, an aqueous solution ofsodium formate and sodium ascorbate was prepared by adding 43.0 grams ofsodium formate and 14.0 grams sodium ascorbate to 43.0 grams of water.The pH of this solution was 8.0 and the water activity 0.55 (RH 55%).Eight grams of this solution was filled into a pouch comprised ofHytrel® film as in Example 1A. When placed in a dry atmosphere (10% RH),this devise emitted 38% water vapor while maintaining a water activitybetween 0.55 (55% RH) and 0.52 (52% RH). When placed in a high humidityenvironment (84% RH) the pouch gained 30% moisture before reaching awater activity of 0.68 (68% RH).

When placed in a 240 ml metalized package at 70 degrees F. with airheadspace, a pouch containing 8.0 grams of this solution consumed 29 mlof oxygen in 20 days.

Example 3B

Example 3 was repeated with the addition of 0.4 grams of 500 mesh ironadded to the 8.0 gram Hytrel® pouch. When placed in a 240 ml metalizedpackage at 70 degrees F. with air headspace, this pouch consumed 46 mlof oxygen in 20 days.

Example 4A

A solution of sodium ascorbate was prepared by adding 30 grams of sodiumascorbate, 0.1 grams of potassium sorbate to 30 grams of water. The pHof this solution was 7.6 and the water activity 0.85 (85% RH). Eightgrams of this solution was placed in a Hytrel® pouch as in Example 1A.When placed in a dry atmosphere (10% RH), this devise emitted 42% watervapor while maintaining a water activity between 0.85 (85% RFI) and 0.83(83% RH).

When placed in a 240 ml metalized package at 70 degrees F. with airheadspace, a pouch containing 8.0 grams of this solution consumed 34 mlof oxygen in 20 days. The pH decreased to 6.1.

Example 4B

Example 4 was repeated with the addition of 0.4 grams of 500 mesh ironadded to the 8.0 gram Hytrel® pouch. When placed in a 240 ml metalizedpackage at 70 degrees F. with air headspace, this pouch consumed 43 mlof oxygen in 20 days. The pH decreased to 6.8.

The descriptions of the embodiments and their applications as set forthherein should be construed as illustrative, and are not intended tolimit the scope of the disclosure. Features of various embodiments maybe combined with other embodiments and/or features thereof within themetes and bounds of the disclosure. Upon study of this disclosure,variations and modifications of the embodiments disclosed herein arepossible, and practical alternatives to and equivalents of the variouselements of the embodiments will be understood by and become apparent tothose of ordinary skill in the art. Such variations and modifications ofthe embodiments disclosed herein may be made without departing from thescope and spirit of the invention. Therefore, all alternatives,variations, modifications, etc., as may become to one of ordinary skillin the art are considered as being within the metes and bounds of theinstant disclosure.

1. A liquid humidity and oxygen control device for use in an enclosurefor maintaining a desired relative humidity and oxygen level of theenclosure, comprising: (a) a water vapor and oxygen permeable and liquidimpermeable pouch, the pouch formed from material comprising a watervapor transmission rate and an oxygen transmission rate and defining aninterior space within the pouch; and (b) an effective amount of ahumidity and oxygen control solution disposed within the interior spaceand comprising: a saturated aqueous salt solution, salts of ascorbateisomers containing an amount of a salt solution from about 5% to 70%salt, and ascorbic acid salts, or isomers thereof, from 5 to 60%,wherein the water vapor transmission rate of the pouch materialcomprises transmission of about 1% to about 50% by weight of the initialpouch contents in a 24-hour period when exposed to an atmosphere of lessthan 10% relative humidity and absorption of about 1% to about 50% byweight of the initial pouch content when exposed to an atmosphere havinga relative humidity of 85%, and wherein the oxygen transmission rate ofthe pouch material is such that 20 in² of the pouch material willtransfer a minimum of 80 ml of headspace oxygen over 20 days at 70degrees F. and atmospheric pressure.
 2. The humidity and oxygen controldevice of claim 1, wherein the salt solution comprises cations andanions, wherein the cations are selected from the group consisting of:lithium, sodium, potassium, calcium, and magnesium, and the anions areselected from the group consisting of chloride, formate, acetate,phosphate, sulfate, citrate, lactate, malate and tartrate.
 3. Thehumidity and oxygen control device of claim 1, wherein the solutionfurther comprises non-ionic substances selected from the groupconsisting of: propylene glycol, glycerin, and at least one simplesugar.
 4. The humidity and oxygen control device of claim 3, wherein theat least one simple sugar is selected from the group consisting of:glucose and fructose and sugar alcohols.
 5. The humidity and oxygencontrol device of claim 4, wherein the sugar alcohol is selected fromthe group consisting of: xylitol, sorbitol and mannitol.
 6. The humidityand oxygen control device of claim 1, wherein the pH of the solution isbetween 6.0 and
 10. 7. The humidity and oxygen control device of claim1, where the solution contains ascorbate isomer salts and/or erythorbicisomer salts.
 8. The humidity and oxygen control device of claim 7,wherein the ascorbate isomer salts comprise sodium salts of ascorbicacid and/or potassium salts of ascorbic acid, and wherein the erythorbicisomer salts comprise sodium salts of erythorbic acid and/or potassiumsalts of erythorbic acid.
 9. The humidity and oxygen control device ofclaim 1, where the salt solution comprises ascorbate and/or erythorbicisomer salts and at least one metal.
 10. The humidity and oxygen controldevice of claim 9, wherein the at least one metal comprises iron. 11.The humidity and oxygen control device of claim 8, wherein the ascorbateisomer salts comprise sodium salts of ascorbic acid and/or potassiumsalts of ascorbic acid, and wherein the erythorbic isomer salts comprisesodium salts of erythorbic acid, and/or potassium salts of erythorbicacid.
 12. The humidity and oxygen control device of claim 1, whereinsaid humidity control solution is thickened by an amount of one or morecompatible viscosity control agents selected from the group consistingof chemically modified cellulose and xanthan gum.
 13. The humidity andoxygen control device of claim 1, wherein the pH of the humidity controlsolution is adjusted by adding an amount of an acid or base selectedfrom the group consisting of citric acid, lactic acid, formic acid,phosphoric acid, phosphate salts, sodium hydroxide, and potassiumhydroxide.
 14. The humidity and oxygen control device of claim 1,wherein said polymeric material of said pouch is selected from the groupconsisting of polyesters, polyamides, poly lactate, polyolefin, andcombinations thereof.
 15. The humidity and oxygen control device ofclaim 1, further comprising a vapor-permeable outer pouch for containingsaid pouch as a further protection against leaks.
 16. The humidity andoxygen control device of claim 1, wherein the solution containselemental iron.
 17. The humidity and oxygen control device of claim 1,wherein the solution contains a ferrous salt.
 18. The humidity andoxygen control device of claim 16, wherein the ferrous salt comprisesferrous sulfate.
 19. A method for controlling the oxygen and humiditywithin an enclosure, comprising: providing an impermeable enclosurecomprising an interior volume and a closure mechanism; contacting theinterior volume with a humidity and oxygen control device comprising:(a) a water vapor and oxygen permeable and liquid impermeable pouch, thepouch formed from material comprising a water vapor transmission rateand an oxygen transmission rate and defining an interior space withinthe pouch; and (b) an effective amount of a humidity and oxygen controlsolution disposed within the interior space and comprising: a saturatedaqueous salt solution, salts of ascorbate isomers containing an amountof a salt solution from about 5% to 70% salt, and ascorbic acid salts,or isomers thereof, from 5 to 60%, wherein the water vapor transmissionrate of the pouch material comprises transmission of about 1% to about50% by weight of the initial pouch contents in a 24-hour period whenexposed to an atmosphere of less than 10% relative humidity andabsorption of about 1% to about 50% by weight of the initial pouchcontent when exposed to an atmosphere having a relative humidity of 85%,and wherein the oxygen transmission rate of the pouch material is suchthat 20 in2 of the pouch material will transfer a minimum of 80 ml ofheadspace oxygen over 20 days at 70 degrees F. and atmospheric pressure.20. The humidity and oxygen control device of claim 19, wherein the saltsolution comprises: cations and anions, wherein the cations are selectedfrom the group consisting of: lithium, sodium, potassium, calcium, andmagnesium, and the anions are selected from the group consisting of:chloride, formate, acetate, phosphate, sulfate, citrate, lactate, malateand tartrate; and non-ionic substances selected from the groupconsisting of: propylene glycol, glycerin, and at least one simplesugar, wherein the pH of the solution is between 6.0 and 10.